远端融合节段选择对退变性脊柱侧后凸患者矫形术后骨盆入射角变化的影响

The influence of different fusion segments on pelvic incidence in patients with degenerative scoliosis

目的:探讨远端不同融合节段对退变性脊柱侧后凸患者矫形术后骨盆入射角(pelvic incidence,PI)变化的影响。方法:回顾性分析2010年5月~2018年4月因退变性脊柱侧后凸于我院行后路矫形长节段融合内固定手术患者的病历资料,男5例,女37例;年龄50~69岁(60.6±6.9岁)。按远端融合节段不同分为两组:融合至L5纳入A组(14例),融合至骨盆纳入B组(28例)。测量并记录两组患者术前的侧凸Cobb角、局部后凸角(regional kyphosis,RK)和术前、术后的腰椎前凸角(lumbar lordosis,LL)、脊柱矢状面平衡(sagittal vertical axis,SVA)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)及骶骨倾斜角(sacral slop,SS),比较两组患者术后PI改变的差异,分析其与术前矢状面参数的关系。结果:两组患者的术前冠状面Cobb角度、RK、内固定节段数、性别分布、年龄均无统计学差异(P>0.05)。A组患者术前和术后PI分别为46.4°±16.7°和44.1°±13.6°,无显著性差异(P=0.104)。B组患者术前PI为50.9°±13.6°,术后减少至44.0°±13.7°,差异有显著性(P<0.05),其中15例(53.6%)患者术后与术前相比PI减少大于5°。术前A组的PI-LL显著小于B组(P=0.015),而LL显著大于B组(P=0.032);两组术后PI改变(ΔPI)有统计学差异(P=0.04)。相关性分析结果显示B组ΔPI与术前PI(P=0.009)、术前LL(P=0.020)、术前PI-LL(P=0.0003)和术前PT(P=0.006)有显著相关性,线性回归分析ΔPI=-3.117+0.201×术前PI-0.116×术前LL。结论:后路矫形长节段融合固定治疗退变性脊柱侧后凸患者中,远端融合至骨盆的患者相较于融合至L5的患者术后更有可能出现PI的显著性降低;融合至骨盆的患者术后PI的显著改变可能与术前较大的PI和术前更大程度的矢状位失平衡相关。

Objectives:To investigate the influence of different fusion segments on pelvic incidence in patients with degenerative scoliosis.Methods:The present study reviewed patients with degenerative kyphoscoliosis who underwent posterior long fusion between May 2010 and April 2018.42 patients were included in our study,andamong which there were 5 males and37 females,with a mean age of 60.6±6.9 years old(50-69).According to different distal fusion segment,patients were divided into two groups,group A(fused at L5,14 patients)and group B(fused at pelvis,28 patients).The Cobb′s angle,regional kyphosis(RK),lumbar lordosis(LL),sagittal vertical axis(SVA),pelvic incidence(PI),pelvic tilt(PT),and sacral slop(SS)were recorded before and after operation.The differences of pelvic incidence postoperatively between the two groups were compared and their relationships with the parameters of sagittal plane before operation were analyzed.Results:There was no significant difference in Cobb′s angle,regional kyphosis(RK),number of internal fixation segments,gender,and age between the two groups at pre-operation.The pelvic incidence changed from 46.4°±16.7°preoperatively to 44.1°±13.6°postoperatively without statistical significance(P=0.104)in group A,while it significantly decreased from 50.9°±13.6°to 44.0°±13.7°(P<0.05)in group B,with a postoperative decrease of more than 5°in 15 patients(53.6%).Inter-group analysis showed that changes in PI,preoperative PI-LL and postoperative LL were significantly different between both groups.Correlation analysis showed that the changes in PI,preoperative LL and PI were significantly associated.The formula provided by the regression analysis wasΔPI=-3.117+0.201×PrePI-0.116×PreLL.Conclusions:In patients with degenerative scoliosis who underwent posterior long segment internal fixation,the pelvic incidence is more possible to decrease significantly in those utilizing S2-alar-illiac screws rather than those fixed distally to L5.The significant change of pelvic incidence in pelvic fixation group may be related to larger PI and greater degree of sagittal imbalance before operation.